Biodegradation of polypropylene by Paenibacillus sp. and Aeromonas sp. isolated from the Mojo Mangrove Forest...

Polypropylene (PP) is a polymer used in various industries because it is lightweight, durable, and easy to process. The presence of polypropylene in aquatic environments will fragment into sizes of 0.05 to 5 mm which causes pollution and disrupts the ecology of mangroves. Isolation of waste-degrading bacteria is one way to address microplastic pollution. This study aims to measure the effectiveness of polypropylene-degrading bacteria isolated from a Mojo mangrove forest. Water and sediment samples were taken from 15 locations, bacterial screening, biodegradation tests using Bushnell Haas media supplemented with polypropylene granules, followed by molecular characterization of the bacteria and enzyme activity testing. Degradation was measured based on the decrease in residual mass, morphological changes, and functional groups in the polymer. Paenibacillus sp. and Aeromonas sp. can degrade polypropylene by 6.41% and 5.22% with a constant of 0.03% and 0.02% per day and a half-life of approximately 228 days and 282 days. FTIR and SEM analysis showed the formation of carbonyl groups and cracks on the PP surface. The bacteria secreted esterase, lipase, and cutinase enzymes at 21.633 U/mL, 12.932 U/mL, and 28.067 U/mL, respectively. Further studies are needed to optimize their biodegradation performance in natural aquatic environments.